This application claims the benefit of Japanese Application No. 2001-334149 filed Oct. 31, 2001.
The present invention relates to an X-ray generating apparatus and more particularly to an X-ray generating apparatus using an X-ray tube.
In an X-ray generating apparatus using an X-ray tube, the X-ray tube is supported by a suitable support member. The support member supports the X-ray tube in such a manner that the focus of the X-ray tube coincides with a predetermined focal position in the X-ray generating apparatus. To this end, the mounting state, i.e., alignment, of the X-ray tube is adjusted.
The support member for supporting the X-ray tube is usually constructed of a metallic material. Since a high voltage of several ten kV or so is applied to the X-ray tube at the time of X-ray radiation, an insulating measure is able to withstand such a high voltage is applied to the support member.
In a certain type of an X-ray generating apparatus, for example in an X-ray generating apparatus of an integrate type in which an X-ray tube is accommodated within a single container together with a high voltage generating circuit, it is difficult to perform an X-ray tube alignment work, which is attributable to the structure of the apparatus. Moreover, since the material of the X-ray tube supporting member is metal, strict conditions are imposed on a measure for insulation.
Therefore, it is an object of the present invention to provide an X-ray generating apparatus which permits easy alignment of an X-ray tube and easy insulation against high voltages.
According to the present invention, for solving the above-mentioned problem, there is provided an X-ray generating apparatus comprising an X-ray tube having a base portion, the base portion having a single screw hole and a plurality of pin holes, the screw hole and the pin holes being formed perpendicularly to an end face of the base portion; a bracket formed by an integral structure of an epoxy laminated glass cloth sheet, the bracket having an abutment face against which the end face of the base portion of the X-ray tube comes into abutment, a screw through hole formed correspondingly to the screw hole and perpendicularly to the abutment face, the screw through hole permitting a screw for threaded engagement with the screw hole to pass therethrough, a plurality of pin through holes formed correspondingly to the plural pin holes and perpendicularly to the abutment face, the pin through holes having the same diameter as the diameter of the corresponding pin holes and permitting pins for insertion into the pin holes to pass therethrough, and a base portion formed in a position spaced in an extending direction of the abutment face from the position where the screw through hole is formed; a screw which is brought into threaded engagement into the screw hole formed in the base portion of the X-ray tube through the screw through hole from the side opposite to the abutment face in the bracket; a plurality of pins which are inserted respectively into the plural pin holes formed in the base portion of the X-ray tube through the plural pin through holes from the side opposite to the abutment face in the bracket; and a substrate to which the base portion of the bracket is mounted.
Thus, in the present invention, a screw through hole and pin through holes, which correspond respectively to a screw hole and plural pin holes formed in an end face of a base portion of an X-ray tube, are formed in an abutment face of a bracket against which the end face of the base portion of the X-ray tube comes into abutment, and a screw and plural pins are inserted into the screw hole and plural pin holes formed in the X-ray tube from the bracket side through the screw through hole and the pin through holes, thereby mounting the X-ray tube to the bracket. Therefore, a positional relation of the X-ray tube to the bracket is established naturally by the plural pins. Besides, since the bracket is formed by an integral structure of an epoxy laminated glass cloth sheet, there is made insulation against high voltages effectively.
For supporting the X-ray tube while keeping the tube spaced a certain distance from the surface of the substrate, it is preferable that the base portion of the bracket have an abutment face for abutment against the substrate and that an extending direction of the abutment face be perpendicular to the extending direction of the abutment face against which the end face of the base portion of the X-ray tube comes into abutment.
For enlarging a creeping distance from the abutment portion of the X-ray tube to the base portion thereof it is preferable that the bracket be bent at substantially right angles at the portion thereof located between the abutment face against which the end face of the base portion of the X-ray tube comes into abutment and the base portion of the bracket.
For preventing offset in the arrangement of pin holes it is preferable that the plural pin holes include two pin holes formed in a pair on mutually opposite sides with respect to the screw hole.
For well-balancing the arrangement of pin holes it is preferable that the two pin holes formed in a pair be positioned symmetrically with respect to the screw hole.
For well-balancing the arrangement of all the pin holes it is preferable that the plural pin holes be positioned at equal intervals on a circumference centered at the screw hole.
For effecting a highly accurate positional control with a reduced number of pins it is preferable that the number of the plural pin holes be four.
For supporting the X-ray tube so that the axis thereof is perpendicular to the abutment face of the bracket, it is preferable that the end face of the base portion of the X-ray tube be perpendicular to the axis of the X-ray tube.
According to the present invention, there can be provided an X-ray generating apparatus which permits easy alignment of an X-ray tube and easy insulation against high voltages.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.